Bed switch



1947. R. A. FLETCHER 2,425,790

BED SWITCH Filed Jan. 12," 1946 ROLAND A.FLETCHER,

INVENTOR ATTORNEY Patented Aug. 19, 1947 UNITED STATES PATENT OFFICE BEDSWITCH Roland A. Fletcher, San Diego, Calif.

Application January 12, 1946, Serial No. 640,822

5 Claims.

This invention relates to weight-actuated switches and is particularlyapplicable for use under a leg of a bed for turning on a night lamp inresponse to the lessening of the Weight on th leg when an occupant ofthe bed gets up.

An object of the invention is to provide a compact and reliable switchstructure so shaped that the actuating member thereof can be placedunder one leg of a bed without raising the leg materially above thelevel of the floor.

Another object is to provide a weight-actuated switch structure that canbe adjusted to function under beds of different weights and for peopleof different weights.

Another object is to provide a compact and rugged unit consisting of aWeight-actuated switch and a lamp controlled thereby which unit can beplaced partially under and partially adjacent the leg of a bed forproviding illumination when an occupant of the bed gets up.

Other more specific objects and features of the invention will becomeapparent from the description to follow of a particular embodiment ofthe invention as illustrated in the drawing, in which:

Fig. 1 is a longitudinal, vertical section through a switch unit inaccordance with the invention;

Fig. 2 is a View partially in plan and partially in section, the sectionbeing taken along the line II-II of Fig. 1;

Fig. 3 is a cross-section taken along the line III-III in Fig, 1; and

Fig. 4 is a schematic diagram showing the elec trical circuit of thedevice.

Referring first to Figs. 1, 2 and 3, the device shown comprises ahousing l containing a switch for controlling a lamp H which may bemounted on top of the housing, while projecting from one side of thehousing In is a member l2 adapted to be placed under a leg [3 of a bedand to respond to variations in the weight of the leg l3 to actuate theswitch and turn the lamp on and oil.

The housing [0 may consist of a metal stamping having end-walls l4 andt5, side-walls I6 and I1, and a top-wall 18, all formed in one piece.The bottom-wall I9 is formed by a separate piece of metal and extendsbeyond the end-wall l as a strip 20 that is doubled back on itself asindicated at 2| and extended almost back to the endwall I5 to constitutethe member [2. The upper portion 22 of this strip may be indented nearits middle as indicated at 23 to receive the foot of the leg I3 andprevent the foot from slipping off the member l2.

The member 12 is preferably formed of relatively heavy, elastic metal sothat it has substantial resistance to bending by the weight of the legI3. However, it is usually undesirable to make the number I2sufiiciently stiif to fully support the weight, and it is preferablyreinforced by a helical compression spring 24, which is interposedbetween the sections 20 and 22 of member 12 and is centered by thedepressed portion 23 of the section 22.

The end of the section 22 adjacent the endwall E5 of the housing It] isprovided with a switch-actuating tongue 25 of insulating material, whichextends through a slot 26 in the endwall l5, into the housing H1. Thetongue 25 may be secured to section 22 by rivets 21.

The contact mechanism within the housing l0 comprises a pair of leafsprings 28 and 29 positioned one above the other and both supported atone end. Thus the lower leaf spring 29 rests upon an insulating block 30which lies upon the bottom-wall I9. A second block of insulatingmateria1 3i rests upon the spring 29 and separates it from the spring28. A third block 32 of insulating material rests upon the spring 28 andextends upwardly through the top-wall I8 of the housing l0 and isprovided with a shoulder 32! which engages the wall I 8. A screw 33extends through an aperture provided therefor in the bottom-wall l9 andis threaded into the insulating block 32. When this screw 33 istightened it compresses the pile consisted of the block 30, the spring29, the block 3|, the spring 28, and the block 32 together, and alsoholds the right end of the bottom-wall [9 against the housing I 0. Aninsulating bushing 34 surrounds the screw 33 within the blocks 30 and3|, to insulate the screw from the contact springs 28 and 29.

As best shown in Fig. 3, the block 32, in addition to functioning as astructural member to support the leaf springs 28 and 29, also functionsas an electrical receptacle. Thus it has a pair of slots 35 and 36 whichopen through its upper surface into recesses 31 and 38, in which springcontacts 39 and 40 are located.

The device is adapted to be energized over a two-conductor lamp cordfrom a common source of lighting current, and to this end a pair ofconductors 4| and 42 are shown entering the endwall 14 of the housingthrough an insulating bushing 43 positioned in an aperture in the wallM. One of these conductors, 4|, is connected directly to the lower leafspring 29, and the other conductor, 42, is connected directly to thereceptacle contact 40. The other receptacle contact 39 is connected by awire 45 (Fig. 3) to the other leaf spring 28; It will be observed,therefore, that,

when the contact springs 28 and 29 are closed, a circuit is completedfrom the supply conductors 4| and 42 to the two contacts 39 and 40 ofthe receptacle, and a lamp connected to the receptacle will be lighted.

As shown in Fig. 1 the lamp II is screwed into a standard form ofreceptacle 41 which has a pair of prongs extending through the slots 35and 36 in the receptacle and making electrical contact with the contacts39 and 40.

If it is desired to have the lamp in some other location, the receptacle41 can [be removed, and an extension cord plugged in.

The contact springs 28 and 29 are provided near their outer ends withcontacts 281 and 29| respectively. The lower contact spring 29 isextended beyond the end of the spring 28 and is adapted to be engaged bythe end of the insulating tongue 25. The upper spring 28 normally bearsagainst an insulating tip 50 on the lower end of a screw 51 which isthreaded through the top-wall l8 of the housing and is provided with ahandle .52 on its upper end.

The device functions as follows:

When the leg l3 of the .bed which is to control the switch is rested inthe recess 23 in the upper section 22 of the member l2, the legdepresses the tongue 25 to a pre-determined extent, dependent upon theweight of the bed. When the bed is not occupied, the contacts 28,! and29.! should be closed, but they should be open when a person is in thebed. Adjustment to provide for the indicated operation is readilyobtained by turning the adjusting screw 5|, while the bed is empty,until the contacts 28I and 29! are just closed, as indicated by lightingof the lamp ll. With this adjustment, any additional weight imposed onthe leg l3, as by a person getting into bed, is surficient to break thecontacts and extinguish the lamp. However, should the person leave thebed at any time during the night the reduction in the weight on the leg13 permits the tongue 25 to move upwardly suflicient to again close thecontacts 281 and 29,] and light the lamp II.

The arrangement has the practical advantage of providing an automaticnight lamp which always lights in response to an occupant of the bedleaving it, without the necessity of the occupant groping around in thedark to find a light switch.

By means-of the adjustment screw 5| the switch can .be adjusted tofunction reliably regardless of the weight of the bed with which it isused and regardless of the weight of the occupant of the bed.Furthermore, if there is more than one occupant of the bed, the switchcan be adjusted to light the lamp in response to rising of only one ofthe occupants.

A particular advantage of the structure is that it provides a rugged andreliable sprin mechanism for supporting the weight of the leg, whichstructure is compact vertically so that it does not lift the leg highoff the floor. The elevation of the leg by the device is sufiicientlysmall to be permissible without correspondingly raising the other threelegs off the floor. However, if desired, small supports of the sameheight as the spring section 22 may be placed under the other legs ofthe bed to maintain all four :corners of the bed at the same level.

Although for the purpose of explaining the invention, a particularembodiment thereof has been described in substantial detail, various.departures from the exact construction disclosed and described can bemade without departing from the invention, and the latter is to belimited only to the extent set forth in the appended claims.

I claim:

1. A device of the type described comprising: a casing defining anenclosure and consisting of a bottom-wall and separate cover meansconstituting side and top walls, said bottom-wall extending laterallybeyond said cover member on one side thereof; the extended portion ofsaid bottom-wall being folded back on itself and having a free endextended toward said cover member at a level below the top of said covermember, switch means in said casing; and means on said free end foractuating said switch means.

2. A device of the type described comprising: a casing defining anenclosure having an opening in one side thereof; a base member extendinglaterally from the bottom of said casing on said one side therof; aweight-supporting vertically defiectable member positioned above saidbase member and secured at its outer end to the outer end of said base.iember; the inner end of said defiectable member extending through saidopening into said casing; and switch means in said casing operable inresponse to vertical movment of the inner end of said deflectablemember; said switch means comprising a pair of leaf spring memberspositioned one above the other and having normally closed electricalcontacts; means coupling the lower spring member to said inner end. ofthe defleotable member whereby .downward movement or" the latter movessaid lower spring member downwardly; and means for adjusting the upperspring member vertically to vary the vertical position of saiddefiectable member which said contacts break.

3. A device of the type described comprising: a casing defining anenclosure having an opening in one side thereof; a base member extendinglaterally from the bottom of said casing on said one side thereof; :aweight-supporting vertically deflectable member positioned above saidbase member and secured at its outer end to the outer end of said basemember; the inner end of said defleetable member extending through saidopening into said casing; and switch means in said casing operable inresponse to vertical movement of the inner end of said deflectablemember; said switch means comprising a pair of leaf spring memberspositioned one above the other and having normally closed electricalcontacts; means coupling the lower spring member to said inner end orthe deflectable member whereby downward movement of the latter movessaid lower spring member downwardly; and an adjusting screw threadedthrough the wall of said casing and contacting the upper spring memberfor vertically adjusting said upper spring member to vary the verticalposition of said deflectable member at which said contacts break.

4. A device of the type described comprising: a casing defining anenclosure and consisting of a bottom wall and separate cover meansconstituting side and top walls, said bottom wall extending laterallybeyond said cover member on one side thereof; the extended portion ofsaid bottom wall being folded back on itself and having .a free endextended toward said cover memher at a level below the top of said covermember; switch means in said casing; means on said free end foractuating said switch means; and means for adjusting said switch meanstovary the movement of said free end requiredto actuate said switchmeans.

5. A switch responsive to occupation ofa bed REFERENCES CITEDcomprising: deflectable spring means adapted to ,b interposed b t th legof a bed and th The following references are of record in the floor anddeflectable in response to variations in file Of h p nt Weight on thebed; a pair of normally closed 5 UNITED STATES PATENTS electricalcontact members; means for shifting one of said contact members incircuit-opening Number N Date direction in response to the deflection ofsaid 2,135,051 Dfilgle 1939 spring means resulting from an increase in2,142,599 Blndel 1939 Weight on said bed; and means for varying the 12,113,320 MCEWBII M y 1933 magnitude of said deflection required to open2,107,333 n b. 1933 said ontact members Wartmann May 13, 1,389,365 KlineAug. 30, 1921 ROLAND A. FLETCHER]. 35,223 Hexamer Feb. 2, 1886

